Larger file downloads slowing up everything else

I did a clean resintall of Win 8.1 Pro x64 last week on my desktop PC and one thing I forgot to check before starting had to do with download speeds. Some months ago, after a Charter system uprade, my larger file downloads with IDM jumped from ~3.6 mb/s max to 8.6 mb/s. The downside was that those faster ones were slowing everything else needing internet connectivity to a crawl. Someone who knew about this, on a forum that I can't find now, had a fix for it, which brought everything back down to the 3.6 mb/s level. I'm forgetting if it was a network settings adjustment within Windows (most likely) or with the router software (TP-Link Archer C8), which I have the cable modem line going through. Anyone know what the adjustment I'm looking for might be? Thanks,

That router has bandwidth control so I suspect you had used that to manage your use. The management is by IP address / range so the reason it's no longer working is probably because your PC has a new IP address outside the managed range.http://www.tp-link.us/resources/docu...r_C8_V1_UG.pdf

Thanks, Paul. a vague recollection tells me you're onto something in looking at the router setup. I just ran "ping 192.168.0.1" on the TCP/IPv4 connection and it looks good, which I assume means my PC is in the managed range. I think there was something else that got adjusted to solve what I'm reporting. Just wish I could find it was in my bookmarks or emails.

You need to know the IP of your PC. This is done with "ipconfig".
Then you need to check what range you have set for bandwidth management. This is in the router settings.
Post the results and we'll advise.

ipconfig = 192.168.0.1, which is the default for connecting to the router, I believe (or do you need my public one?) Does the bandwidth control screenshot give what you're looking for? I did the basic setup, where NAT Boost is the default, but just disabled it for the bandwith one. Thanks,

Followup: The downside of the enabling bandwidth control as it is, is that speeds dropped on the Charter test from 66 mb/s down and 4.45 mb/s up to 1.3 down and 0.4 up. Switching back to NAT Boost sent them back up to 8.8 mbps

192.168.0.1 = your router
69.145.62.229 = ?
Your PC should have an address somewhere between 192.168.0.2 and 192.168.0.254. If it does not then it is likely that your network adapter is not set to "obtain an address automatically".
The easiest way to determine your machine config is to post the output from this command - the output will appear in Notepad:
ipconfig /all > %temp%\ip.txt & notepad %temp%\ip.txt

Your IP address is 192.168.0.101, assigned by the router. This is good.

I'm not sure how bandwidth control on that router works, but I'd try this and see how it goes.
Add the range 192.168.0.2 - 192.168.0.254 and set the max bandwidth to 8mbps.
Now test several machines at once and hopefully the router will throttle the machine trying to use all the bandwidth.

Paul, the router link, http://tplinklogin.net/, hasn't been able to connect to the server since Friday night. Thought it was just a site down, but now wondering if could it be something else. The cable connections look ok and my laptop and iPad connect to the router (5G), though not to that URL, so not sure what else to look for. The only I'm not sure about is that three lights are on, where I thought that four are normal, but could be wrong there.